Dimeric fluorosurfactants for ink-jet inks

ABSTRACT

The present disclosure provides dimeric fluorosurfactants related methods and ink-jet inks incorporating such fluorosurfactants. As such, an ink-jet ink can comprise a liquid vehicle; a non-ionic fluorosurfactant dimer having the structure CF 3 (CF 2 ) x (CH 2 ) y (CR 2 CR 2 O) z -A-(OCR 2 CR 2 ) a (CH 2 ) b (CF 2 ) c CF 3 , where R is independently H or methyl, A is a bridging unit containing aliphatic or aromatic functionality, x is 3 to 18, y is 0 to 8, z is 0 to 100, a is 0 to 100, b is 0 to 8, and c is 3 to 18; and a colorant.

BACKGROUND

Digital inkjet printing of signs and other graphic arts applications isincreasingly replacing screen printing and other analog printingtechnologies. Digital inks for large format printing should provide goodimage quality, durability, and permanence. While many of the inks in useare solvent-based, in recent years efforts have been made to replaceorganic solvent-based inks with water-based inks. However, many of themedia substrates are nonporous coated papers or polymer films such asvinyl, which presents challenges with respect to water-based inks.

More specifically, nonporous media present wetting and image qualitycontrol issues for aqueous inks due to a combination of low mediasurface energies and low porosity. On nonporous media, dropletcoalescence and subsequent ink flow leads to image quality defects, suchas intercolor bleeding and mottled area fill non-uniformities. Varioussurfactant additives have been used previously in order to effectivelywet low surface energy media and control image quality defects, such ascolor-to-color bleed and area fill mottle. These additives are used inan attempt to provide desired wetting properties and to perform well ina high-speed thermal or piezo printhead.

Materials that have been used include nonionic fluorosurfactants withperfluorinated chains of C8 or larger, but these materials areincreasingly being replaced with short-chain analogs due to stewardshipconcerns (C6 or lower). One drawback of the short-chain materials isthat the lower hydrophobicity typically provides poorer wetting andimage quality control in inkjet printing than traditional longer-chainperfluorinated materials, and this ultimately limits the throughput ofhigh-speed inkjet printing. Thus, the development of specific additivesand ink formulations that improve image quality control would be anadvancement in the art.

DETAILED DESCRIPTION

It has been recognized that traditional fluorosurfactants can bereplaced with non-ionic fluorosurfactant dimers to provide excellentbleed and coalescence while maintaining good printhead operability andcolloidal stability of the ink. As such, the present disclosure isdirected to modifications of nonionic fluorosurfactants (FS—OH) whereFS—OH refers to a general fluorosurfactant structure (FS) with hydroxyl(OH) functionality. Specifically, such FS—OH compounds can be modifiedwith difunctional aliphatic or aromatic isocyanates to make dimericaddition compounds that provide enhancements in image quality whenincorporated into an inkjet ink. The following scheme provides thegeneral reaction to form the dimeric structure:FS—OH+OCN—R—NCO→FS—C(O)NH—R—NHC(O)—FSwhere R is an aliphatic or aromatic group.

It is noted that when discussing the present compositions, inks, andmethods, each of these discussions can be considered applicable to theother of these embodiments, whether or not they are explicitly discussedin the context of that embodiment. Thus, for example, in discussing abridging group in an ink-jet ink having a non-ionic fluorosurfactantdimer, such a bridging group can also be used in a method of making anon-ionic fluorosurfactant dimer, and vice versa.

The present dimeric fluorosurfactants provide improved image quality ininkjet ink formulations while maintaining good printhead operability andcolloidal stability of the ink.

Non-ionic fluorosurfactant dimer compositions and associated methodsdescribed herein can include a non-ionic fluorosurfactant dimer havingthe following structure:CF₃(CF₂)_(x)(CF₂)_(y)(CR₂CR₂O)_(z)-A-(OCR₂CR₂)_(a)(CH₂)_(b)(CF₂)_(c)CF₃,where R is independently H or methyl, A is a bridging unit containingaliphatic or aromatic functionality, x is 3 to 18, y is 0 to 8, z is 0to 100, a is 0 to 100, b is 0 to 8, and c is 3 to 18. In one example, xand c can independently be 3 to 5, y and b can independently be 0 to 4,and z and a can independently be 0 to 25. In one aspect, y and b and zand a can be at least 1. In another example, a+b+y+z is at least two. Inone aspect, x and c can be the same, y and b can be the same, and/or zand a can be the same. In one specific aspect, x and c can be 5. In oneexample, the bridging unit containing aliphatic or aromaticfunctionality can contain 1 to 100 carbons atoms; i.e. C1 to C100. Inone aspect, the bridging unit containing aliphatic or aromaticfunctionality can be a C1 to C50.

Generally, monomer starting materials used to prepare the dimericaddition compounds are nonionic fluorosurfactants of the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)H, where R is independently H ormethyl, x is 3 to 18, y is 0 to 8, and z is 0 to 100.

Such monomer starting materials include nonionic fluorosurfactants suchas, but not limited to, S550-100 or S550 (Chemguard), S222N (Chemguard),S559-100 or S559 (Chemguard), Capstone® FS-31 (DuPont™) Capstone® FS-35(DuPont™), Capstone® FS-34 (DuPont™), Capstone® FS-30 (Dupont™),Capstone® FS-3100 (Dupont™), Masurf® FS-2950 (Mason), Masurf® FS-3240(Mason), Masurf® FS-2900 (Mason), Masurf® FS-2825 (Mason), Masurf®FS-1700 (Mason), Masurf® FS-1800 (Mason), and Megaface 550 (DIC), ormixtures thereof. Starting materials can be treated prior to reactionwith the isocyanate bridging unit to remove water and/or hydroxylicsolvents by drying or other methods known to those in the art.

Bridging groups can be derived from difunctional isocyanates, althoughother chemistries can be envisioned. Suitable diisocyanates for thebridging group A include those represented by the formula R(NCO)₂, whereR represents an organic group having a molecular weight of about 120 to400. In one example, the diisocyanates can include those in which Rrepresents a divalent aliphatic hydrocarbon group having 4 to 10 carbonatoms, a divalent cycloaliphatic hydrocarbon group having 5 to 15 carbonatoms, a divalent arylaliphatic hydrocarbon group having 7 to 15 carbonatoms, or a divalent aromatic hydrocarbon group having 6 to 15 carbonatoms.

Examples of the suitable organic diisocyanates include1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3- and -1,4-diisocyanate,1-isocyanato-2-isocyanatomethyl cyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl-cyclohexane (isophoronediisocyanate or IPDI), bis-(4-iso-cyanatocyclohexyl)-methane,2,4′-dicyclohexyl-methane diisocyanate, 1,3- and1,4-bis-(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3- and/or -1,4-xylylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanatomethyl cyclohexane, 2,4- and/or2,6-hexahydrotoluylene diisocyanate, 1,3- and/or 1,4-phenylenediisocyanate, 2,4- and/or 2,6-toluylene diisocyanate, 2,4- and/or4,4′-diphenyl-methane diisocyanate, 1,5-diisocyanato naphthalene, andmixtures thereof.

Dimeric addition compounds prepared from nonionic fluorosurfactantmonomers (B) and dimeric isocyanate-derived bridging groups (A) cancomprise or consist of the following homo and hetero combinations ofmonomer(s) and bridging groups(s), or blends of monomer and dimer:

i) dimers with a single bridging group: BAB;

ii) blends of dimers with multiple bridging groups: BAB+BA′B, where A′is a different bridge than A;

iii) heterodimers with multiple monomer groups: BAB′, where B′ is adifferent monomer than B; and

iv) blends of monomer and dimer, including mixtures of combinations ini-iii: B+BAB (or B′+BAB).

The present disclosure also relates to the use of the dimericfluorosurfactants in inkjet ink formulations. With the above in mind, anink-jet ink can comprise a liquid vehicle; a non-ionic fluorosurfactantas disclosed herein, including the monomer/dimer blends of the typedefined in i-iv above; and a colorant.

While the amount of fluorosurfactant monomer/dimer blend present in anyparticular composition can vary, in one example, the non-ionicfluorosurfactant dimer can be present in an ink-jet ink at aconcentration from 0.01 wt % to 5 wt %, and the monomericfluorosurfactant can be present in a concentration from 0 wt % to 4.99wt %, where the total of monomer+dimer is from 0.01 w % to 5 wt %. Inone aspect, the combination of non-ionic fluorosurfactant dimer andmonomer can be present in an ink-jet ink at a concentration from 0.1 wt% to 2.5 wt %.

As used herein, “liquid vehicle” or “ink vehicle” refers to the liquidfluid in which a fluorosurfactant dimer is placed to form an ink. In oneexample, the ink can also include a colorant. Ink vehicles are wellknown in the art, and a wide variety of ink vehicles may be used withthe systems and methods of the present invention. Such ink vehicles mayinclude a mixture of a variety of different agents, including,surfactants, solvents, co-solvents, anti-kogation agents, buffers,biocides, sequestering agents, viscosity modifiers, surface-activeagents, water, etc. Though not part of the liquid vehicle per se, inaddition to the colorants, the liquid vehicle can carry solid additivessuch as polymers, latexes, UV curable materials, plasticizers, etc.Additionally, the term “aqueous liquid vehicle” or “aqueous vehicle”refers to a liquid vehicle including water as a solvent. In one aspect,water can comprise a majority of the liquid vehicle.

Generally the colorant discussed herein can include a pigment and/ordye. As used herein, “dye” refers to compounds or molecules that impartcolor to an ink vehicle. As such, dye includes molecules and compoundsthat absorb electromagnetic radiation or certain wavelengths thereof.For example, dyes include those that fluoresce and those that absorbcertain wavelengths of visible light. Generally, dyes are water soluble.Furthermore, as used herein, “pigment” generally includes pigmentcolorants, magnetic particles, aluminas, silicas, and/or other ceramics,organo-metallics or other opaque particles. In one example, the colorantcan be a pigment.

In addition to the above ink-jet inks, the present disclosure providesan ink-jet ink comprising: a liquid vehicle; a non-ionicfluorosurfactant dimer having the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)-A-(OCR₂CR₂)_(a)(CH₂)_(b)(CF₂)_(c)CF₃,where R is independently H or methyl, A is a bridging group containingaliphatic or aromatic functionality, x is 3 to 18, y is 0 to 8, z is 0to 100, a is 0 to 100, b is 0 to 8, and c is 3 to 18; and a polymer.Notably, the present ink-jet ink does not require a colorant. As such,the present ink-jet ink can be used as a separate pretreatmentcomposition that is printed with an ink composition to improve imageproperties. In one example, the polymer can be a fixer polymer, e.g., acationic polymer. As used herein, “fixer polymer” refers to a polymerhaving an ionic charge opposite that of a colorant such that thecolorant binds to or otherwise becomes associated with the polymersufficient to immobilize the colorant on the printed image upon contactwith the polymer. In another example, the polymer can be a latex. Asused herein, “latex” or “latex particulate” refers to discrete polymericmasses dispersed in a fluid, e.g., water. In still another aspect, theink-jet ink pretreatment can include a multivalent salt, e.g. calciumnitrate, for use as a fixing agent.

The monomers used in the latexes can be vinyl monomers. As such, themonomers can be selected from the group of vinyl monomers, acrylatemonomers, methacrylate monomers, styrene monomers, combinations thereof,and mixtures thereof.

In one example, the monomers can be selected from the group of vinylmonomers, acrylate monomers, methacrylate monomers, styrene monomers,ethylene, vinyl chloride, vinylidene chloride, maleate esters, fumarateesters, itaconate esters combinations thereof, and mixtures thereof. Inone aspect, the monomers can include acrylates, methacrylates, andstyrenes. Additionally, the monomers can include hydrophilic monomersincluding acid monomers, and hydrophobic monomers.

Monomers that can be polymerized in forming the latex particulatesinclude, without limitation, styrene, p-methyl styrene, α-methylstyrene, methyl methacrylate, hexyl acrylate, hexyl methacrylate, butylacrylate, butyl methacrylate, ethyl acrylate, ethyl methacrylate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, propyl acrylate,propyl methacrylate, octadecyl acrylate, octadecyl methacrylate, stearylmethacrylate, vinylbenzyl chloride, isobornyl acrylate,tetrahydrofurfuryl acrylate, 2-phenoxyethyl methacrylate, benzylmethacrylate, benzyl acrylate, ethoxylated nonyl phenol methacrylate,ethoxylated behenyl methacrylate, polypropyleneglycol monoacrylate,isobornyl methacrylate, cyclohexyl methacrylate, cyclohexyl acrylate,t-butyl methacrylate, n-octyl methacrylate, lauryl methacrylate,tridecyl methacrylate, alkoxylated tetrahydrofurfuryl acrylate, isodecylacrylate, isobornyl methacrylate, isobornyl acrylate, dimethyl maleate,dioctyl maleate, acetoacetoxyethyl methacrylate, diacetone acrylamide,N-vinyl imidazole, N-vinylcarbazole, N-vinyl-caprolactam combinationsthereof, derivatives thereof, and mixtures thereof.

Acidic monomers that can be polymerized in forming the latexparticulates include, without limitation, acrylic acid, methacrylicacid, ethacrylic acid, dimethylacrylic acid, maleic anhydride, maleicacid, vinylsulfonate, cyanoacrylic acid, vinylacetic acid, allylaceticacid, ethylidineacetic acid, propylidineacetic acid, crotonoic acid,fumaric acid, itaconic acid, sorbic acid, angelic acid, cinnamic acid,styrylacrylic acid, citraconic acid, glutaconic acid, aconitic acid,phenylacrylic acid, acryloxypropionic acid, aconitic acid, phenylacrylicacid, acryloxypropionic acid, vinylbenzoic acid, N-vinylsuccinamidicacid, mesaconic acid, methacroylalanine, acryloylhydroxyglycine,sulfoethyl methacrylic acid, sulfopropyl acrylic acid, styrene sulfonicacid, sulfoethylacrylic acid, 2-methacryloyloxymethane-1-sulfonic acid,3-methacryoyloxypropane-1-sulfonic acid, 3-(vinyloxy)propane-1-sulfonicacid, ethylenesulfonic acid, vinyl sulfuric acid, 4-vinylphenyl sulfuricacid, ethylene phosphonic acid, vinyl phosphoric acid, vinyl benzoicacid, 2-acrylamido-2-methyl-1-propanesulfonic acid, combinationsthereof, derivatives thereof, and mixtures thereof.

Regarding the latex particulates, the latexes can have various particlesizes, and molecular weights. In one example, the latex particulates mayhave a weight average molecular weight (M_(w)) of about 5,000 to about500,000. In one aspect, the latex particulates can have a weight averagemolecular weight (M_(w)) ranging from about 100,000 to about 500,000. Insome other examples, the latex resin has a weight average molecularweight of about 200,000 to 300,000.

Further, the average particle diameter of the latex particles can befrom about 10 nm to about 1 μm; in some other examples, from about 10 nmto about 500 nm; and, in yet other examples, from about 100 nm to about300 nm. The particle size distribution of the latex is not particularlylimited, and either latex having a broad particle size distribution orlatex having a mono-dispersed particle size distribution may be used. Itis also possible to use two or more kinds of latex particles each havinga mono-dispersed particle size distribution in combination.

The ink-jet ink and other compositions of the present disclosure canalso be suitable for use on many types of substrates of recording media,including but not limited to, paper media and nonporous media. In oneexample, the substrate can be nonporous vinyl media.

Typical ink vehicle formulations described herein can include water, andcan further include co-solvents present in total at from 0.1 wt % to 40wt %, depending on the jetting architecture, though amounts outside ofthis range can also be used. Further, additional non-ionic, cationic,and/or anionic surfactants can be present, ranging from 0.01 wt % to 10wt %. In addition to the colorant or the latex, the balance of theformulation can be purified water, or other vehicle components known inthe art, such as biocides, viscosity modifiers, materials for pHadjustment, sequestering agents, preservatives, and the like.

Classes of co-solvents that can be used can include organic co-solventsincluding aliphatic alcohols, aromatic alcohols, diols, glycol ethers,polyglycol ethers, caprolactams, formamides, acetamides, and long chainalcohols. Examples of such compounds include primary aliphatic alcohols,secondary aliphatic alcohols, 1,2-alcohols, 1,3-alcohols, 1,5-alcohols,ethylene glycol alkyl ethers, propylene glycol alkyl ethers, higherhomologs (C₆-C₁₂) of polyethylene glycol alkyl ethers, N-alkylcaprolactams, unsubstituted caprolactams, both substituted andunsubstituted formamides, both substituted and unsubstituted acetamides,and the like.

Consistent with the formulation of this disclosure, various otheradditives may be employed to enhance the properties of the inkcomposition for specific applications. Examples of these additives arethose added to inhibit the growth of harmful microorganisms. Theseadditives may be biocides, fungicides, and other microbial agents, whichare routinely used in ink formulations. Examples of suitable microbialagents include, but are not limited to, NUOSEPT® (Nudex, Inc.),UCARCIDE™ (Union carbide Corp.), VANCIDE® (R.T. Vanderbilt Co.), PROXEL®(ICI America), and combinations thereof.

Sequestering agents, such as EDTA (ethylene diamine tetra acetic acid),may be included to eliminate the deleterious effects of heavy metalimpurities, and buffer solutions may be used to control the pH of theink. From 0 wt % to 2 wt %, for example, can be used. Viscositymodifiers and buffers may also be present, as well as other additivesknown to those skilled in the art to modify properties of the ink asdesired. Such additives can be present at from 0 wt % to 20 wt %.

In addition to the above, a method of manufacturing an ink-jet ink cancomprise admixing a colorant and a nonionic fluorosurfactant into aliquid vehicle; wherein the non-ionic fluorosurfactant dimer includesany of those described herein including having the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)-A-(OCR₂CR₂)_(a)(CH₂)_(b)(CF₂)_(c)CF₃,where R is independently H or methyl, A is a bridging unit containingaliphatic or aromatic functionality, x is 3 to 18, y is 0 to 8, z is 0to 100, a is 0 to 100, b is 0 to 8, and c is 3 to 18. In one example,the method can further include admixing a latex into the liquid vehicle.

Further, in addition to the non-ionic fluorosurfactant dimers describedherein, the present disclosure provides for methods of making suchdimers relating thereto. Generally, a method of manufacturing anon-ionic fluorosurfactant dimer(s) can comprise reacting a monomer ormixture of monomers with a diisocyanate or mixture of diisocyanates toform the non-ionic fluorosurfactant dimer(s). Such materials can bereacted to form the blends of monomer/dimers as discussed herein,depending on the reaction stoichiometry.

The non-ionic fluorosurfactant dimers can be generally manufactured fromreacting their respective alcohol monomers with a difunctional moleculeto form dimers. As such, the monomers can be chosen to provide symmetricand asymmetric dimers as previously discussed.

In one example, a method of manufacturing a non-ionic fluorosurfactantdimer can comprise reacting a first monomer having the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)H and a second monomer having thestructure CF₃(CF₂)_(c)(CH₂)_(b)(CR₂CR₂O)_(a)H, where R is independentlyH or methyl, x is 3 to 18, y is 0 to 8, z is 0 to 100, a is 0 to 100, bis 0 to 8, and c is 3 to 18 with a difunctional molecule having thestructure R(NCO)₂ where R is an organic group having a molecular weightof about 120 to 400. The reaction is carried out to form the non-ionicfluorosurfactant dimer with the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)-A-(OCR₂CR₂)_(a)(CH₂)_(b)(CF₂)_(c)CF₃,where R is independently H or methyl, A is a bridging group containingaliphatic or aromatic functionality, x is 3 to 18, y is 0 to 8, z is 0to 100, a is 0 to 100, b is 0 to 8, and c is 3 to 18.

In one aspect, the difunctional molecule can be an alkyl diisocyanate.In one specific aspect, the diisocyanate can be1,6-hexamethylenediisocyanate. As such, upon reacting with the monomers,the difunctional molecule can provide a bridging group that includes anamide group.

Regarding the present method steps, such steps can be performed in anumber of sequences and are not intended to be limited to the orderwritten. For example, the second monomer can be reacted with thedifunctional molecule before the first monomer is reacted with thedifunctional monomer, and vice versa. Additionally, it is noted that anyand all combinations of such steps or individual step may be performedsequentially or simultaneously. For example, reacting the first monomerwith the difunctional monomer and reacting the second monomer with thedifunctional monomer may be performed sequentially or may be performedsimultaneously.

Additionally, it is to be understood that this disclosure is not limitedto the particular process steps and materials disclosed herein becausesuch process steps and materials may vary somewhat. It is also to beunderstood that the terminology used herein is used for the purpose ofdescribing particular examples only. The terms are not intended to belimiting because the scope of the present disclosure is intended to belimited only by the appended claims and equivalents thereof.

It is be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the context clearly dictates otherwise.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary.

Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to include allthe individual numerical values or sub-ranges encompassed within thatrange as if each numerical value and sub-range is explicitly recited. Asan illustration, a numerical range of “about 1 to about 5” should beinterpreted to include not only the explicitly recited values of about 1to about 5, but also include individual values and sub-ranges within theindicated range. Thus, included in this numerical range are individualvalues such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4,and from 3-5, etc. Additionally, a numerical range with a lower end of“0” can include a sub-range using “0.1” as the lower end point.

EXAMPLES

The following examples illustrate some embodiments of the presentink-jet ink compositions and methods that are presently known. However,it is to be understood that the following are only exemplary orillustrative of the application of the principles of the presentcompositions and methods. Numerous modifications and alternativecompositions and methods may be devised by those skilled in the artwithout departing from the spirit and scope of the present compositionsand methods. The appended claims are intended to cover suchmodifications and arrangements. Thus, while the present ink setcompositions and methods have been described above with particularity,the following examples provide further detail in connection with whatare presently deemed to be the acceptable embodiments.

Example 1—Fluorosurfactant Dimer Preparation

A 3-neck flask was charged with Chemguard S550-100 fluorosurfactant(59.62 g, dried over 4 Å molecular sieves). The flask was equipped witha mechanical stirrer, temperature probe, and a nitrogen bubbler andstirred under nitrogen for one hour. 1,6-hexamethylene diisocyanate (4.0g, Fluka >98%) was added dropwise with stirring. Dibutyltindilaurate(0.05 g, Sigma-Aldrich) was added, and the flask was fitted with aheating mantle. The clear yellow solution was heated to 65° C.,accompanied by a slight exotherm to 77° C. and the appearance ofturbidity. The resulting mixture was stirred for 7 hours at 65° C., andthen left 14 hours at room temperature. Deionized water (1.2 g) wasadded dropwise, and the mixture was heated to 65° C. Additionaldeionized water (130 g) was added, giving a yellow slurry. After sixhours, the material was cooled and rinsed from the flask with deionizedwater (100 g). After sitting 10 days, a viscous yellow solution wasobtained. Yield: 280 g (22% solids). NCO content: none detectable.Surface tension of 0.1 wt % solution in water was 18.3 vs. 17.0 dynes/cmfor the starting material.

LC/MS analysis confirmed the presence of monomer, dimer, and other (fromthe starting material). (LTQ-Orbitrap LC-MSn system. MS to MS4 data werecollected for the peak identifications. The LC column was an AgilentEclipse Plus C18, 50 mm×2.1 mm, particle size 1.8 μm.) LC/ELSD analysisquantified that 43:50:7 blend of monomer:dimer:polyethylene glycol wasobtained. (Agilent 1100 LC system with AllTech 2000 evaporative lightscattering detector. The LC column was an Agilent Eclipse Plus C18, 50mm×2.1 mm, particle size 1.8 μm).

Example 2—Pretreatment Preparation

A pretreatment composition was prepared by admixing the fluorosurfactantdimer of Example 1 with a liquid vehicle and cationic polymer accordingto Table 1. The measured surface tension was 19.6 dynes/cm.

TABLE 1 Compositional Elements Pretreatment (g) 2-Pyrrolidinone 33.7MPDiol 18.2 Non-ionic surfactant 2 Cationic Polymer (55% solution) 8.8Fluorosurfactant Dimer Blend 3.7 from Example 1 Deionized Water 133.6

Example 3—Ink-Jet Ink Preparation

Three KCMYcm ink sets were formulated. A first ink set having thefluorosurfactant dimer blend of Example 1 was prepared according toTables 2 and 3A, a second ink set having the fluorosurfactant dimerblend of Example 1 with a fluorosurfactant was prepared according toTables 2 and 3B, and a comparative ink set having the fluorosurfactantmonomer of Example 1 with a fluorosurfactant was prepared according toTables 2 and 3C. The ink-jet inks were prepared according to thecompositional elements and amounts (in grams) listed in Tables 2 and3A-C.

TABLE 2 Ma- Yel- Light Light Black Cyan genta low Magenta Cyan Component(g) (g) (g) (g) (g) (g) Magenta — — 42.8 — 10.7 — Pigment DispersionBlack Pigment 20.0 — — — — — Dispersion Cyan Pigment — 14.9 — — — 3.7Dispersion Yellow Pigment — — — 29.1 — — Dispersion Acrylic Latex 32.832.8 32.8 32.8 18.7 18.7 Dispersion Wax Dispersion 4.0 4.0 4.0 4.0 2.52.5 2-pyrrolidinone 29.5 30.5 33.7 33.7 33.7 32.9 MPDiol 18.2 18.2 16.016.7 17.6 18.2 Anionic 0.4 0.4 0.4 0.4 0.4 0.4 Surfactant Nonionic 3.63.6 3.6 3.6 3.6 3.6 Surfactant Acrylic Polymer — — — — 3.3 2.7 SolutionChelating Agent 0.5 0.5 0.5 0.5 0.5 0.5 Chemguard Var Var Var Var VarVar S550-100 Example 1 Var Var Var Var Var Var DI Water Bal Bal Bal BalBal Bal Total 200 200 200 200 200 200 MPDiol is 2-methyl-1,3-propanediolVar is variable; i.e., providing the amounts listed in Tables 3A-C Balis balance of grams up to 200 g

-   Tables 3A-C: Ink Sets with surfactant amounts, estimated    monomer/dimer ratios, and surface tensions

TABLE 3A Ink Set 1 Light Light (Higher Dimer) Black Cyan Magenta YellowMagenta Cyan Example 1 (wt %) 0.4 0.5 0.9 0.8 0.6 0.5 Chemguard — — — —— — S550-100 (wt %) Monomer (wt %) 0.2 0.2 0.4 0.3 0.3 0.2 (calculated)Dimer (wt %) 0.2 0.3 0.4 0.4 0.3 0.3 (calculated) Surface Tension 20.920.2 20.0 20.0 20.2 20.3 (dynes/cm)

TABLE 3B Ink Set 2 Light Light (Lower Dimer) Black Cyan Magenta YellowMagenta Cyan Example 1 (wt %) 0.2 0.3 0.5 0.5 0.4 0.3 Chemguard 0.1 0.20.3 0.3 0.2 0.2 S550-100 (wt %) Monomer (wt %) 0.2 0.3 0.5 0.5 0.4 0.3(calculated) Dimer (wt %) 0.1 0.2 0.3 0.2 0.2 0.2 (calculated) SurfaceTension 20.8 20.5 20.0 20.2 20.3 20.4 (dynes/cm)

TABLE 3C Ink Set 3 Light Light (Higher Dimer) Black Cyan Magenta YellowMagenta Cyan Example 1 (wt %) — — — — — — Chemguard 0.4 0.5 0.9 0.8 0.60.5 S550-100 (wt %) Monomer (wt %) 0.3 0.5 0.8 0.7 0.6 0.5 (calculated)Dimer (wt %) — — — — — — (calculated) Surface Tension 22.2 21.2 20.420.8 20.8 20.4 (dynes/cm)

Example 4—Data

The ink sets of Example 3 were printed on a modified HP L25500 printerequipped with a heating system onto Avery MPI3100 self-adhesive vinyl,followed by curing in the printer at 95° C.

Color combinations of various colors and color densities were printedand assessed for visual print quality under two conditions:

Test 1: the samples were printed at a printer printzone setpoint of 55°C. without pretreatment. All ink sets printed well, with good imagequality and print reliability over multiple plots. Samples were visuallygraded for area fill uniformity. Qualitative grading criteria includingmottle (light/dark density variations) and pinhole defects fromnon-uniform wetting of the media. The overall rank of the samples forarea fill uniformity was set 1 (higher dimer)>set 2 (lower dimer)>set 3(no dimer).

Test 2: samples were printed at a printzone temperature of 25° C. alongwith an underprinted pretreatment fluid from Example 2. The inks andpretreatment printed well, with good print reliability. The overallprint quality was dependent on the amount of underprinted pretreatment,which was adjusted in the image as a ratio of the total ink density:Samples were visually graded for area fill uniformity as a function ofpretreatment. Qualitative grading criteria including mottle (light/darkdensity variations) and pinhole defects from non-uniform wetting of themedia. The overall rank of the samples for area fill uniformity was set1 (higher dimer)>set 2 (lower dimer)>set 3 (no dimer). Sets 1 and 2 wereshown to control image quality defects using lower amounts ofpretreatment than Set 3.

The results in test 1 and test 2 show that the presence of a dimericfluorosurfactant in an inkjet ink improved the image quality over themonomeric fluorosurfactant.

While the disclosure has been described with reference to certainembodiments, those skilled in the art will appreciate that variousmodifications, changes, omissions, and substitutions can be made withoutdeparting from the spirit of the disclosure. It is intended, therefore,that the present disclosure be limited only by the scope of thefollowing claims.

What is claimed is:
 1. An ink-jet ink, comprising: a liquid vehicle; anon-ionic fluorosurfactant dimer having the structureCF₃(CF₂)_(x)(CH₂)_(y)(CR₂CR₂O)_(z)-A-(OCR₂CR₂)_(a)(CH₂)_(b)(CF₂)_(c)CF₃,where R is independently H or methyl, A is a bridging unit containingaliphatic or aromatic functionality, x is 5, y is 0 to 8, z is 0 to 100,a is 0 to 100, b is 0 to 8, and c is 5; and a colorant.
 2. The ink-jetink of claim 1, wherein y and b are independently 0 to 4 and z and a areindependently 0 to
 25. 3. The ink-jet ink of claim 2, wherein a+b+y+z isat least two.
 4. The ink-jet ink of claim 1, wherein the non-ionicfluorosurfactant dimer is present in the ink-jet ink at a concentrationfrom 0.01 wt % to 5 wt %.
 5. The ink-jet ink of claim 1, wherein thebridging group is a diisocyanate having the structure R(NCO)₂ where R isan organic group having a molecular weight of about 120 to
 400. 6. Theink-jet ink of claim 1, wherein the non-ionic surfactant dimersurfactant is selected from the group consisting of a dimer with asingle bridging group having the structure BAB; a blend of two dimerswith multiple bridging groups having the structure: BAB+BA′B; aheterodimer with multiple monomer groups having the structure: BAB′; anda blend of a monomer and a dimer having the structure: B+BAB or B′+BAB;wherein B is a monomer, B′ is a monomer that is different than B, A isthe bridging group, and A′ is a bridging group that is different than A.7. The ink-jet ink of claim 1, wherein y and b are the same or z and aare the same.
 8. The ink-jet ink of claim 1, further comprising from 0.1wt % to 40 wt % of a co-solvent.